Many workers at a South Korean company in Ho Chi Minh City skipped lunch Thursday after maggots were seen in one tray.

Ham Hyeong Jo, director of the Dong Nam Vietnam Company, told the Tuoi Tre newspaper in a Sunday report that the company is working with the lunch supplier to address the problem.

Jo said he would end the contract if the supplier makes a similar mistake again.

The discovery of maggots and similar lunch problems has been increasingly reported from factories across Vietnam. Many workers have passed out after eating while others have done so after refusing to eat.

A report from the Vietnam Food Safety Department last month said there were 927 cases of food poisoning between 2007 and 2011, with 229 people dying and 30,733 people being hospitalized.

It said food served at companies, mostly in industrial parks and export processing zones in Ho Chi Minh City and nearby Dong Nai and Binh Duong Provinces, accounted for more than 20 percent of the cases. The substandard food and working conditions have led to many wildcat strikes.

A Thanh Nien investigation found factory owners looked to serve cheap meals to cut costs. The employers used to pay VND8,000-10,000 (US$0.34-$0.48) for a meal a few years ago and this has increased to VND10,000-12,000 at present.